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Information about the atomic icebreaker Yamal
- The vessel is one of five Arktika class ice-breakers leased to the Murmansk Shipping Company by the Russian Government (her sisters are Arktika [Launched in 1975], Sibir [1978], Rossiya [1985] and Sovetskiy Soyuz [1990]).
- The name is derived from a Nenets word meaning 'End of the Earth', also applied to the Yamal Peninsula.
- Her keel was laid on 25 May 1986 in St Peterburg and she was launched on 28 October 1992.
- Registered number M43048 and International Call Sign UCJH.
- Length overall 150 m, at waterline 136 m. Breadth overall 30 m, at waterline 28m. Draft 11¨08 m.
- Height, keel to mast head; 55 m on 12 decks (4 below water).
- Ice knife, a 70 cm thick steel casting, is situated about 22 m aft of the prow.
- Displacement 23 455 tonnes; capacity 20 646 gross registered tons.
- The cast steel prow is 48 cm thick at its strongest point.
- The hull is double with water ballast between them. The outer hull is 48mm thick armour steel where ice is met and 25mm elsewhere.
- Eight bulkheads allow the icebreaker to be divided into 9 watertight compartments.
- Ice breaking is assisted by an air bubbling system (delivering 24 m3 s-1 from jets 9 m below the surface), polymer coatings, specialized hull design, and capability of rapid movement of ballast water. Ice may be broken while moving ahead or astern.
- An MI-2 or KA-32 helicopter is carried for observing ice conditions ahead of the vessel.
- The icebreaker is equipped to undertake close tow operations when assisting other vessels through ice.
- Search lights and other high intensity illuminations are available for work during winter darkness.
- Complement 128; 48 officers and 80 other ranks.
- Power is supplied by 2 pressurized water KLT-40 nuclear reactors, each containing 245 enriched Uranium fuel rods.
- Each reactor weighs 160 tonnes, both are contained in a closed compartment under reduced pressure.
- Fuel consumption is approximately 300 gm a day of heavy isotopes when breaking thick ice. 500 kg of Uranium isotopes are contained in each reactor when fully fuelled. This allows about 5 years between changes of the reactor rods at current operating conditions.
- Shielding of the reactor is by steel, high density concrete, and water. The chain reaction can be stopped in 0¨6 seconds by full insertion of the control rods.
- Used cores are extracted and new ones installed in Murmansk, spent fuel is reprocessed, and waste is disposed of at a nuclear waste plant.
- Ambient radiation is monitored by 86 sensors distributed throughout the vessel. In accommodation areas this is 10 to 12µRöntgen h-1, within the reactor compartment, at 50% power, 800µRöntgen h-1.
- The primary cooling fluid is water which passes directly to 4 boilers for each reactor, steam is produced at 30kgcm-2 (310°).
- Main propulsion system: each set of boilers drives 2 steam turbines which turn 3 dynamos (thus 6 dynamos may operate). 1kVDC is delivered to 3 double wound motors connected directly to the propellers.
- Electricity for other purposes is provided by 5 steam turbines turning dynamos which develop a total of 10MW.
- There are 3 propellers; starboard and midships ones turn clockwise, port turns counter-clockwise. Shafts are 20m long. Screw velocity during normal operations is between 120 and 180 rpm.
- Propellers are fixed, 5¨7 m diameter and weigh 50 tonnes, each has four 7 tonne blades fixed by 9 bolts (16tonne torque applied); inspection wells allow them to be examined in operation.
- Four spare blades are carried; diving and other equipment is aboard so a blade may be replaced at sea, each operation takes from 1 to 4 days (3 such changes have been necessary on Arktika icebreakers since 1975).
- A propulsive effort of 480 tonnes can be delivered with 18¨43 MW (25 000 shaft horse-power) from each screw (total 55¨3 MW [75 000 shaft horse-power]).
- Power can be controlled at a rate of 1% a second (thus 200 seconds from full ahead to full astern).
- An over-run of an additional 10% is possible in exceptional circumstances
- Maximum speed is 22 knots (40 km h-1); full speed in open water is 19¨5 knots (35 km h-1); breaking ice 2¨3m thick can be done at 3knots (5¨5 km h-1) continuously.
- Maximum ice thickness which can be penetrated while navigating is estimated as 5m; individual ridges exceeding 9m thick have been broken through.
- Helm controls one rudder, which turns 35° either way, operated by 4 hydraulic cylinders powered by one of 2 pumps. It is protected by an ice-horn for moving astern.
- Steering may also be provided by directing air jets of the bubbling system (comparable to use of bow-thrusters).
- Auxiliary power is available from 3 Diesel generating sets; 1 MW (1x) and 250 kW (2x).
- Anchors: two 7 tonne anchors with 300 m of chain each, and 4 ice anchors.
- Five deck cranes are aboard, the largest pair can lift 16 tonnes each.
- Sea water distillation; 2 vacuum stills can supply 5 m3 of fresh water an hour each (240 m3 a day).
- A 1000 m3 differential ballast tank is situated fore and aft, and a pair of 300 m3 tanks each side athwart the vessel; the main pumps are capable of moving 1m3 of water a second.
- There are 1280 compartments (cabins, storage areas, machine rooms, etc).
- Sufficient provisions and supplies can be carried to operate for 7 months.
- Safety equipment includes: 1 launch (crew 10, others 50), 2 fully enclosed lifeboats (88 persons each), and 18 inflatable life rafts. An immediate deployment 'man-overboard' emergency launch and 18 life belts are on stand-by.
1st July 2001